Tennis post



July 17, `1923.

R. R. HIRST ET AL TENNIS POST,

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Filed Aug. 7. 1922 Patented July 17, 1927?.

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I, BJOLllll'J` RUSHXVORTH HIRST ANB` ARNLD HIRST, 0F HALIFAX, FNGLAND.`

TENNIS POST.

Application filed August 7, 1922. Serial No. 580,376.

To 'all w hom t 'may concern.

Be it known that we, RowLAND RUSH- won'rir Hrns'r and ARNOLD Hms'r, subjects oi King George Voi Great Britain, residing at Halifax, in the county ot York, England, have invented a new and useful Improvement in Tennis Posts,oi which the followin is a specification.

his invention relates to they posts used to support the net in the game of tennis. i Asis well known, these posts carry means to strain between them a wire or cord'to which the net is attached, and in order that the upper edge of the net may be horizontal.l the straining eiiect on the net wire or cord must be very considerable.

4lt is necessary, therefore, that the posts be made very strong, but at the same time this strength cannot be provided at the expense ot weight, that is to say the post must not be too heavy to be handled comfortably by a .groundsman or player. i

The posts are commonlymade oit wood, andnotwithstanding the most careful selection and seasoning of the material, breakage and distortion of these wooden posts, under the great strain imposed upon them, very tre uently occurs.

ollow metal posts have been employed in order to get the requisite strength, but as it is vdesirable that the upper ends ot the posts shall have a rounded or spherical shape it has hitherto been necessary, in order to obtain this, to insert into the upper end of a metal tube a plug of metal or wood having i the desired external contour and secured by brazing or other means.

Certain constructions or types of net-- straining gear also call for the fitting of a guide pulley for the net wire centrally ci the top of the post, and to enable this to be done in the case of a tubular metal post a plug or iitting of some description has had to be employed.

The object of this invention is to provide a metal post approximately in diameter the ordinary wooden post and having a rounded or spherical head or upper end integral with the metal of which the post is composed. rlhe thicknessoi such rounded or spherical upper end can thus be made or kept the same as that of the body, and the weight of the post be kept at a practical amount, such head also having provision if required, for the fitting of a guide pulley centrally oi the Say post without the application ot any fittingv or cap of any kind.

ln order to enable the inventionand the manner in which it is carried into practice' Fig. 5 illustrates the manner in which the spherical or rounded head of the'post is formed.

According to, and for the purposes of, theI invention a tube a of a suitable ductile metal, of steel, of the proper diameter and of the requisite length is taken, and at the end which is to form the to i of the post there are out out on diametrica ly opposite sides et the tube, two portions yof the approximate shape illustratedat b in Fig. l. The` .Width or the gap at the apex is approximately that of the guide pulley to be subsequently accommodated.

he end oft the tube having been thus prepared it is heated, and on the proper working heat being attained, there is inserted into the tube a mandrel or plug c the c of which is rounded or curved to the radius of the post less the thickness of the metal so that said plug corresponds to the inner surface or section of the finished head.

'lf he opposite end of they plug or mandrel comes flush with the lower end of the tube or has a collar or enlargement.c2 against which the end of the tube bears.

The plug c having been inserted., the tube is then paced into a, die CZ having a rounded or curved inner end CZ corresponding to the exterior shape ot the finished head. Pressure is applied by any suitable means such as a screw press, lever press, drop hammer or the like to close the die upon the two leaves or portions cz, a of the tube end, and cause them to be curved inwardly and moulded to the shape of the die.

The mandrel c or die cl may have a print to 'fashion the slot e for the reception of the guide pulley, but in practice it is found liu preferable to so proportion the cut out portions Z tliat the closing` in of the tube end by the die .Will leave a slot of somewhat narrower Width than is required, which slot .is then enlarged ,and accurately finished by milling o-r"l'ike operation.

it' no provision is required to be made for a guide pulley in the post head, thel cut out portions Z) are made sinal'ler .by an amount which will cause the edges of the leaves or portions. a, .a to -nicely abut and make a. vq ood joint under :the action ot vthe d-ie. Such meeting,` portions may be suitably depressed .to forni a. `central .groove across the post head for the cord to rest in, and the Vmeeting.edges of .the leaves, ifso formed into a groove, are preferably 'brazed, or otherwise joined to present any liability of damage to the cord.

Through unequal contraction of the metal when cooling, a .certain amount of distortion `from the .true curvature `may be apparent after the lirst pressing operation, in which case the post. head is re-heated and subjected -to a second 'pressing operation in a iinishing` die to leave it of true curvature.

lifter the post head has been formed as above set .forth and the plug or mandrel removed, the slot e is milled out to the exactshape required, and an opening f cut, if desired, in the side of the post to admit of the insertion of a winding barrel. Openings g, g and 7L, 7i are also formed in the post, to receive the spindles of the guide pulley and Winding barrel, if the post is fashioned toreceive these parts, f

By the method ,and Ameans above set forth, there can be produced what has hitherto been unattainable, namely a tubular steel or other metal tennis post. having a rounded or spherical upper end or head integral With and of -the same thickness as the body of the 100St, and it ,is further rendered possible t0 make provision, integral With a tubular `metal post, for a centrally disposed guide pulley, to apply which it has hitherto been necessary to employ a separate cap or fitting.

Having thus described our invention, what We lclaim as new and desire to Secure by ters Patent is 1. A tennis post formed .of a straight cy.- lindrical tube .of ductile metal provided with longitudinal notches haring curved converging sides, said notchesbeing tormed in the upper end of the tube andthe metal between the notches bei-ng :bent to 'hemfispherical form so that the tivo notches form a single continuous' opening, the hemispherical .end portion of the tube 'being .of the saine diameter and thickness las'its main portion and having holes for receiving .the lspindle of a guide pulley.

2. A tennis post as set forth in claim l, and having' also an opening` .of greater Width than ythe said opening and formed longitudinally in the Vmain portion of the tube and communicating at its upper end With one end ot the aforesaid opening, and the main portion of the tube having Ahelles for receiving the spindle of a Winding barrel.

In testimonyY whereof We a-HiXour signatures.

ROWLAND RUSHl/VORTH rlR-ST. ARNOLD HIRST. 

